Cytomegalovirus Latency

The group of herpesvirus’ are a unique type of virus that can lie dormant. This means that these viruses will infect the body (host) and feed off of them, causing illness. The interesting thing about this group, which includes Cytomegalovirus, is that they can stay within the hosts’ body tissues without causing disease symptoms. The virus simply remains within the body, causing no harm. This is called latency, or lying dormant. The dormant period is when the virus is not causing any harm. Something can then trigger the disease to reactivate and cause symptoms. Let’s dive into this thought a little more.

So once the virus goes away, how does it come back again? Well, there are a couple ways that a dormant virus can be reactivated to cause symptoms. The first reason is because the body is sick with something else. Things like a common cold or the flu can start to infect the body and reactivate a dormant virus to wreak havoc on the immune system, making the host sick. The other way that this can happen is in an attempt to fight off those infections. Sometimes the body uses these cells to try and fight off other foreign invaders of the immune system but it gets a little carried away and actually ends up doing more harm than good.

Usually a healthy individual does not experience symptoms; this is a topic I have covered in other posts about Cytomegalovirus. The virus does not want to attack a healthy immune system because they will most certainly be beat. The other option for the cell is the lytic pathway which is where the virus replicates within the host and rapidly releases the disease-causing molecules. This makes a person sick right away. Latency is a benefit to the virus because they can live comfortably within the host cells, feeding off of them and evolving- even if they are not physically causing harm. The cause and timing of reactivation of the virus is highly dependent on the host. Everyone is different and every environment is different. Viruses adapt to their environment and try to evolve and survive no matter who their host is. This is why latency works so well for Cytomegalovirus.

 

SOURCES

Grinde, Bjorn. 25 October, 2013. Herpesviruses: latency and reactivation- viral strategies and host response. NCBI. Website

Brown, Jay C. 1 February, 2017. Herpes Simplex Virus Latency: The DNA Repair-Centered Pathway. Hindawi. Website